Repair of ballistic concrete panels

ABSTRACT

A ballistic panel formed with a ballistic material, the panel comprising: a panel with a filled void; wherein the filled void is filled with a ballistic replacement material; and wherein the filled void exhibits ballistic properties equivalent to the ballistic panel formed with the ballistic material; wherein the ballistic replacement material and the ballistic material comprise between about 1121 kg/cubic meter (about 70 pounds per cubic foot) and about 1442 kg/cubic meter (about 90 pounds per cubic foot); and wherein the ballistic replacement material and the ballistic material comprise: about 1 part by mass Portland cement; about 0.5 to 1.5 part by mass fine aggregate; and about 0.0005 to 0.05 part by mass air entrainment additive; about 0.005 to 0.15 part by mass fiber; about 0.005 to 0.05 part by mass aluminum hydroxide and about 0.005 to 0.05 part by mass calcium phosphate.

CROSS REFERENCE TO RELATED APPLICATIONS

This nonprovisional utility patent application is related to and claimspriority from one or more prior filed nonprovisional and provisionalapplications. The present application is a Continuation-in-Part of U.S.Non-provisional patent application Ser. No. 14/268,435 filed May 2,2014, which claims the benefit of U.S. Provisional Patent ApplicationNo. 61/818,873 filed May 2, 2013, each of which is incorporated hereinby reference in its entirety. The present application also claimspriority to and the benefit of U.S. Provisional Patent Application No.62/352,700, filed Jun. 21, 2016, which is incorporated herein byreference in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

This disclosure relates generally to equipment and methods to repairconcrete barriers, in particular ballistic concrete barriers used fortraining facilities used for training with live ammunition.

SUMMARY OF THE DISCLOSURE

This summary is meant to provide an introduction to the concepts thatare disclosed within the specification without being an exhaustive listof the many teachings and variations upon those teachings that areprovided in the extended discussion within this disclosure. Thus, thecontents of this summary should not be used to limit the scope of theclaims that follow.

Inventive concepts are illustrated in a series of examples, someexamples showing more than one inventive concept. Individual inventiveconcepts can be implemented without implementing all details provided ina particular example. It is not necessary to provide examples of everypossible combination of the inventive concepts provide below as one ofskill in the art will recognize that inventive concepts illustrated invarious examples can be combined together in order to address a specificapplication.

The present invention relates to ballistic panels with filled voids. Thefilled voids are filled with a ballistic replacement material, and thefilled voids exhibit ballistic properties equivalent to the ballisticpanel.

It is an object of this invention to provide a ballistic panel formedwith a ballistic material, the panel including a panel with a filledvoid filled with a ballistic replacement material; and wherein thefilled void exhibits ballistic properties equivalent to the ballisticpanel formed with the ballistic material, and wherein the ballisticreplacement material and the ballistic material comprise between about1121 kg/cubic meter (about 70 pounds per cubic foot) and about 1442kg/cubic meter (about 90 pounds per cubic foot); and wherein theballistic replacement material and the ballistic material comprise:about 1 part by mass Portland cement; about 0.5 to 1.5 part by mass fineaggregate; and about 0.0005 to 0.05 part by mass air entrainmentadditive; about 0.005 to 0.15 part by mass fiber; about 0.005 to 0.05part by mass aluminum hydroxide and about 0.005 to 0.05 part by masscalcium phosphate.

These and other aspects of the present invention will become apparent tothose skilled in the art after a reading of the following description ofthe preferred embodiment when considered with the drawings, as theysupport the claimed invention.

Other systems, methods, features and advantages of the disclosedteachings will be or will become apparent to one with skill in the artupon examination of the following figures and detailed description. Itis intended that all such additional systems, methods, features andadvantages be included within the scope of and be protected by theaccompanying claims.

BRIEF DESCRIPTION OF THE FIGURES

The disclosure can be better understood with reference to the followingfigures. The components in the figures are not necessarily to scale,emphasis instead being placed upon illustrating the principles of thedisclosure. Moreover, in the figures, like reference numerals designatecorresponding parts throughout the different views.

FIG. 1 is a side view of a first injector assembly positioned to fill avoid in a ballistic panel.

FIG. 2 is a side view of the first injector assembly.

FIG. 3 is a front view of the first injector assembly.

FIG. 4 is a top view of the first injector assembly.

FIG. 5 shows a ballistic panel with a vent hole above the plywoodfaceplate, steel plate with connected second steel nipple.

FIG. 6 is a side view of a second injector assembly positioned to fill avoid in a ballistic panel.

FIG. 7 is a side view of the second injector assembly.

FIG. 8 is a front view of the second injector assembly.

FIG. 9 is a top view of the second injector assembly.

FIG. 10 shows a sequence of steps to prepare to deliver replacementmaterial to repair a void.

FIG. 11 shows a sequence of steps to fill the void.

FIG. 12 shows a sequence of steps to process the replacement materialafter removal of the injector assembly.

FIG. 13 summarizes the process for making ballistic concrete made withchemical air entrainment additive rather than foam.

FIG. 14 illustrates a sequence of steps associated with retrofitting apreexisting wall to provide bullet resistance, according to oneembodiment of the present invention.

FIG. 15 illustrates a front view of a wall with a first layer ofballistic paver blocks according to one embodiment of the presentinvention.

FIG. 16 illustrates a front view of a wall with a first and second layerof ballistic paver blocks according to one embodiment of the presentinvention.

FIG. 17 illustrates a front view of a wall with three layers ofballistic paver blocks according to one embodiment of the presentinvention.

FIG. 18 illustrates a side view of a finished wall with three layers ofballistic paver blocks and drywall according to one embodiment of thepresent invention.

FIG. 19 illustrates an example embodiment of blocks with two bevelededges according to the present invention.

DETAILED DESCRIPTION

In the following description, like reference characters designate likeor corresponding parts throughout the several views. Also in thefollowing description, it is to be understood that such terms as“forward,” “rearward,” “front,” “back,” “right,” “left,” “upwardly,”“downwardly,” and the like are words of convenience and are not to beconstrued as limiting terms.

Referring now to the drawings in general, the illustrations are for thepurpose of describing a preferred embodiment of the invention and arenot intended to limit the invention thereto.

The present disclosure teaches the creation of components made from wetballistic concrete prepared without an addition of preformed foam, asdisclosed in U.S. Pat. No. 9,121,675 issued Sep. 1, 2015 by Amidon et alfor Barrier for Absorbing Live Fire Ammunition and Uses Thereof; U.S.patent application Ser. No. 14/268,435, filed May 2, 2014 by Amidon etal. for Repair of Ballistic Concrete Panels; and U.S. patent applicationSer. No. 13/449,420, filed Apr. 18, 2012 by Amidon et al. for Barrierfor Absorbing Very High Power Bullets and Uses Thereof; all incorporatedherein by reference in their entirety.

FIG. 1 is a side view of an injector assembly connected to a ballisticpanel with a void. More specifically, FIG. 1 shows a ballistic panel 104with a base 120 on the ground 124 or some other support surface. Aproximal face 112 of the ballistic panel 104 has a void 108 extendingfrom the proximal face 112 a portion of the distance to the distal face116. Ballistic panels 104 may be used in live-fire training where aseries of panels are used to create one or more structures such as abuilding or a faux tank to allow military or police personnel to trainwith live ammunition. The ballistic panels are designed to receive theprojectile and retain the projectile so that trainees are not injured byricochets. The ballistic panels 104 may also be used as backstops orsafety barriers behind conventional targets or behind ballistic panelshoot houses or other structures.

The ballistic panels 104 may be used in a variety of sizes. Theballistic panels 104 may have a thickness between the proximal face 112and the distal face 116 of approximately 24 to 30 inches. The thicknessmay be selected based upon the properties of the ballistic concrete usedfor the ballistic panel 104 and the anticipated kinetic energy of theammunition. Thus, a ballistic panel for a backstop behind a pistol rangemay be a different thickness from a ballistic panel intended to stoprounds from a M-16 rifle (sometimes called AR-15 rifle), or to stoprounds from a 50 caliber machine gun or sniper rifle.

Repeated hits of a ballistic panel 104 in approximately the samelocation will degrade the panel and begin to create a void 108. In orderto maintain the integrity of the ballistic panel 104 as a barrier, thesevoids 108 need to be filled with material compatible with the purpose ofthe ballistic panel as a bullet absorbing barrier.

FIG. 1 shows an injector assembly 200 connected to a faceplate 140 whichis removably attached to the proximal face 112 of the ballistic panel104 by a set of screws 144 (See FIG. 5). The faceplate 140 may be threequarter inch birch plywood. The screws 144 may be concrete anchors.Optionally, a support beam 150 may be cut to the size needed to supportthe injector assembly 200 in a substantially horizontal orientation withrespect to an opening in the faceplate 140 (discussed below). Thesupport beam 150 helps support the injector assembly 200 as the injectorassembly 200 will be filled with replacement material (not shown here)loaded into the injector assembly 200 through an opening on the top endof the injector assembly 200 that is accessible after removing a cap204. Once the injector assembly 200 is at least partially filled withreplacement material and the cap 204 replaced, air pressure may be usedto inject the replacement material into the void through the use ofinlet valve 208 and outlet valve 212.

FIG. 2 is a side view of the injector assembly 200. The majority of theinterior volume for receipt of replacement material is found within wye216 and forty-five degree elbow 220 (hereinafter elbow 220). Theinjector assembly 200 shown in FIG. 2 uses PVC pipe and a variety ofmetallic components. One of skill in the art knows that when switchingfrom PVC pipe materials to metal components there is often an adapter.If someone built an entire injector assembly out of brass or some othermetal, the injector assembly may lack certain adapters as they would notbe needed.

FIG. 2 shows the use of a four inch PVC wye which is schedule 80. Thenominal pipe sizes and schedules are part of the North American set ofstandard sizes for pipes where the pipe size is a nominal diameter andthe schedule indicates wall thickness.

FIG. 2 shows an elbow 220 that is also a four inch PVC schedule 80component. A four inch PVC adapter 224 (Schedule 40) attached to theupper end of the elbow 220 (such as by gluing). A four inch PVC nipple228 (Schedule 80) is connected to the adapter 224. A four inch aluminumcoupling adapter 232 is connected to the lower end of cap 204. A cap 204such as a four inch aluminum dust cap along with the coupling adapter232 may be repeatedly removed and replaced from the threaded top end ofthe coupling adapter 232. A preferred way to quickly remove the cap 204from the injector assembly 200 is through the use of two-piece cap witha camlock. The lower portion of the cap 204 is threadedly engaged withthe injector assembly 200 and the top portion of the cap is connected tothe bottom portion of the cap with a camlock, which is a fluid fittingknown to those of skill in the art for ease of rapidly disconnecting andconnecting a fitting. A threaded engagement could be used to disconnectand connect the cap 204 to the injector assembly 200 as the injectorassembly is repeatedly filled with replacement material, but threads maybe fouled during the introduction of replacement material so a camlockmay be a better choice. The combination of the cap 204 and the couplingadapter 232 may be called the cap assembly 202.

The horizontal leg of the wye 216 is shown with a pair of PVC reducerbushings 240 (Schedule 80) that reduce the diameter from a nominal fourinches to a nominal two inches. On the inlet end 160 of the wye 216,reducer bushing 240 is connected to a second reducer bushing 244 whichis a PVC schedule 80 reducer bushing to reduce from a two inch nominaldiameter to a one half inch nominal diameter. A one half inch brassnipple 248 may be threaded into the second reducer bushing 244. An inletvalve 208 may be threadedly connected to the brass nipple 248. The inletvalve 208 may have a one half inch brass ball valve 252 with inlet valvehandle 256. The inlet end 160 of the inlet valve 208 may have a one halfinch to one quarter inch brass bushing 262. A one quarter inch malecoupler 266 may extend from the bushing 262 to allow an air hose (notshown) from a compressed air source to be connected to the inlet valve208.

Connected to the reducer bushing 240 on the outlet end 164 of the wye216 is a first steel nipple 274. A second steel nipple 278 is connectedto a steel plate 282. The outlet valve 212 may be connected betweensteel nipples 278 and 274. The outlet valve 212 may by a two inchnominal diameter PVC knife valve with outlet valve handle 286. Those ofskill in the art will recognize that there are a number of differentvalve designs that are used with fluids but will also recognize thatsome valve designs are more prone to fouling from the sand and grit inthe replacement material so certain valve choices will be more reliableand durable than other choices. Many of the viable choices will be typesof gate valves such as knife valve, slide valve (sometimes calledguillotine valve), or wedge valve. The valve may be made out of brass orsome other material and those of skill in the art will be able to makeany required transition from PVC piping to brass.

As discussed in greater detail below, the injector assembly 200 may havea pressure regulator before the inlet valve 208 so that the air pressureapplied to the injector assembly 200 may be regulated at the inlet ofthe injector assembly 200 rather than relying on the operator toproperly set the compressed air source to limit output to a particularprescribed pressure limit. For example the pressure regulator may be setat 25 PSIG as that pressure provides a pressure gradient to move thereplacement material into the void but does not lead to applying to muchpressure to the injector assembly 200. A pressure gage used without apressure regulator may be included before the inlet valve to provide aneasy to monitor indication to the operator of the pressure that will beapplied to the injector assembly 200 if the inlet valve 208 is opened.This indication provides a warning to the operator that the compressedair source may need to be adjusted if the pressure gage is notindicating a pressure within a prescribed range.

Alternatively, the pressure gage may be used after the pressureregulator and before the inlet valve 208 to offer a confirmation of theproper operation of the pressure regulator.

While injector assemblies may be made of various sizes, an injectorassembly 200 as shown in FIG. 2 may have a total length of approximatelytwenty-seven inches from the distal face 288 of steel plate 282 to theinlet end 160 of the male coupler 266. The end to end length may belonger if a pressure regulator or pressure gage is added to the inletend of the inlet valve 208.

FIG. 3 is a front view of injector assembly 200. Several componentsintroduced during the discussion of FIG. 2 are visible from a differentperspective in FIG. 3. Steel plate 282 is shown with the distal face 288which would be facing the proximal face 112 of ballistic panel 104 (seeFIG. 1). The steel plate 282 would be separated from the proximal face112 of ballistic panel 104 by faceplate 140 which is sized to extendbeyond the void 108 in all directions. The injector assembly outlet 290is aligned with an opening in faceplate 140 to allow injection of aslurry of replacement material into the void 108.

Also visible in FIG. 3 are previously introduced components: cap 204;coupling adapter 232; nipple 228; adapter 224; elbow 220; wye 216;outlet valve 212; and outlet valve handle 286.

While injector assemblies 200 may be made of various sizes, an injectorassembly 200 as shown in FIG. 3 may have a total height of approximatelytwenty inches from the lower end of the steel plate 282 to the top ofcap 204.

FIG. 4 is a top view of injector assembly 200. This view showscomponents previously introduced from another view. Moving from theinlet end 160 to the outlet end 164, the visible components are: inletvalve 208 with inlet valve handle 256; reducer bushing 240; cap 204;elbow 220 (barely visible in this view); wye 216; reducer bushing 240;first steel nipple 274; outlet valve 212 with outlet valve handle 286;second steel nipple 278; and steel plate 282.

Sequence of Repair Steps.

FIG. 10 shows a sequence of steps 1000 to prepare to deliver replacementmaterial to repair a void. FIG. 11 shows a sequence of steps 2000 tofill the void. FIG. 12 shows a sequence of steps 3000 to process thereplacement material after removal of the injector assembly 200. Thoseof skill in the art will recognize that some of the steps in these threefigures may be done in parallel or the sequence of some steps may bereversed if one step does not require prior completion of another step.The order of the steps presented is not to be deemed as limiting unlessthe relationship between steps is specified.

Prepare to deliver replacement material.

STEP 1004—Prepare the void 108 for repair. Using rubber gloves (andtrowel as appropriate), clean out the void, removing any loose material.Ballistic concrete contains fiber material and there will be fibersextending into the cleaned out void from the ballistic panel. Thesefibers may be left as is. Fibers remaining in and around the void 108will help the replacement material to bind to the existing material inthe ballistic panel.

STEP 1008—Prepare the replacement material in accordance withmanufacturer's instructions. The process for creating suitablereplacement material may include periodically stopping the mixingprocess to weigh a sample such as a quarter cubic foot sample to checkif the sample indicates that the replacement material is within a targetrange for weight per cubic foot. Additional processing may be needed todecrease the weight per cubic foot of the replacement material into asuitable range.

STEP 1012—Once the replacement material is created to manufacturer'sspecification, note the time, as there may be a need to use the newlymade replacement material within a specified time period. For example,the newly created replacement material may need to be used withinseventy-five minutes of creation.

STEP 1016—Prepare a Test Cylinder. The test cylinder is used to confirmthat the ballistic properties of the replacement material are suitablefor the intended use. Ballistic properties include depth of penetration,angle of ricochet, fragmentation, delamination/detachment. The testcylinder should be of an appropriate size for the required test process.Fill test cylinder to the top, and level off using the screed tool. Snapthe plastic cover on and write the date and time of mix and the locationof the repair on the test cylinder. After the test cylinder passesballistic testing after adequate curing of the replacement material, therepair is successful. For example, some replacement material may requiretesting fourteen days after filling the test cylinder.

The precise requirements of the testing process may vary with theintended use of the ballistic panel 104. An example of a ballistic testis testing performed utilizing an M-16 A-2 with a twenty inch barrel orequivalent. The round used is a 5.56 caliber 62 grain green tip round.The round shall be fired from a distance of not greater than 82 feet.Place one round into the center of the cylinder. Measure the depth ofthe penetration by utilizing a measurement probe. The measuredpenetration depth should be within the range of one inch to five inchesfor acceptance. The penetration depth may be measured to the trailingedge of the projectile as measuring to the leading edge of theprojectile may not be convenient. A measured penetration depth outsideof those parameters means that the replacement material is not suitablefor the intended use and the repair should be removed and replaced.

Step 1020—Take measurements to prepare to mount the faceplate/proximalplate assembly. The proximal plate may be the steel plate 282 or anotherproximal plate such as the aluminum faceplate 1282 discussed below or ananalogous plate that connects the outlet of the outlet valve to theopening of the faceplate and the proximal side of the void.

A piece of plywood or other flat surface serves as the faceplate 140(FIG. 1). The proximal plate such as steel plate 282 and second steelnipple 278 are connected together with the injector assembly outlet 290of the steel plate 282 aligned with an opening in the faceplate 140.Take measurements of the opening of the void 108 and mark the proximalface 112 of the ballistic panel 104 to help in aligning the injectorassembly outlet 290 with the approximate center of the opening of thevoid 108. The marks need to be sufficiently distant from the opening ofthe void 108 so that the faceplate 140 may be placed over the void 108without covering the alignment marks.

Optionally, measure and record the length of the void 108 at thehorizontal midline of the void 108 as this measurement may be useful forpositioning the vent hole. (discussed below)

Step 1024—Wet the repair area inside and around the void 108 using aspray bottle with water (not shown). There should be no puddling orponding of water, but the area should be saturated to the point of beingthoroughly damp. The purpose of the wetting is to keep the existingballistic material surrounding the void 108 from quickly drawing waterout of the replacement material.

Step 1028—Place the faceplate/proximal plate assembly over the void 108and align the injector assembly outlet 290 with the approximate centerof the opening of the void 108 using the alignment marks.

Step 1032—Using a concrete drill and masonry bit, drill holes throughthe plywood faceplate 140 into the ballistic concrete around the void108. These holes are for use with fasteners to hold the faceplate 140 tothe proximal face 112 of the ballistic panel 104. A set of six holes maybe adequate depending on the size of the faceplate 140. The six holesmay be arranged with two holes to the right and to the left of the voidand one hole above and below the void. Other patterns may be used. Asballistic concrete differs from conventional concrete, it may benecessary to modify the normal instructions for pilot holes forfasteners. For example, for a fastener used in conventional concretethat normally uses a one quarter inch pilot hole, it may be useful touse a pilot hole made with a three-sixteenth inch drill bit.

Step 1036—Drill the vent hole. Take one half the previously measuredlength of the void opening and mark a spot above the centerline of theopening in the proximal plate such as second steel nipple 278. Drill avent hole using a three-quarter inch masonry bit at approximately aforty five degree angle so that the drill bit breaks through theexisting ballistic material into the void 108 about halfway towards theback of the void 108. This will provide a vent hole 312 to allow air toleave the void 108 as replacement material is injected into the void108. While the vent hole 312 shown in FIG. 5 is drilled through thefaceplate 140, those of skill in the art will recognized that dependingon the size and placement of the faceplate 140, the vent hole 312 couldbe drilled above the top edge of the faceplate 140. While a single venthole 312 may be sufficient for many applications, those of skill in theart will recognize that the process may include more than one vent hole,especially for a larger or irregularly shaped void.

Those of skill in the art will recognize that some modification on thestarting point and angle of the vent hole may be appropriate for anunusually shaped void.

Alternatively, the vent hole can be placed an inch or so above the topof the proximal plate such as steel plate 282 and the vent hole can bedrilled at a horizontal or slight downward angle to intersect with thevoid. As the operation of the injector assembly is apt to drivereplacement material to the back of the void 108, the void 108 will fillfrom the back to the front. A small gap may occur along the front wallof the void 108 as material may fill the vent hole 312 before the topportion of the front of the void 108 is filled. This small gap can befilled with troweled material during the surface clean up after removingthe faceplate 140.

FIG. 5 shows the status after the completion of the preceding step.Visible in FIG. 5 are the plywood faceplate 140 and the steel plate 282with connected second steel nipple 278. A set of eight fasteners 304connecting steel plate 282 to faceplate 140 is visible in FIG. 5. Thefasteners 304 may be sheetrock screws of appropriate length for thechoice of faceplate 140 such as three quarters inch birch plywood.Should a fastener protrude from the distal face of the faceplate 140,the tip of the fastener may be broken off or otherwise removed. Minorsurface imperfections caused by the fastener 304 extending beyond thedistal face of the faceplate 140 may be corrected at the end when otherimperfections are addressed.

Two of the fasteners 308 which hold the faceplate 140 to the proximalface 112 of ballistic panel 104 are visible. Also visible is theproximal opening of the vent hole 312.

Note an analogous view of this step using injector assembly 1200(discussed below) would show proximal plate 1280 and the holes forconnecting the outlet pipe 1278 to the outlet valve 1212.

Step 1040—Screw the rest of the injector assembly to the second steelnipple 278. When done, the cap 204 should be the highest point of theinjector assembly 200 so that a slurry of replacement material may bepoured into the injector assembly 200 with the cap 204 removed.

Step 1044—Measure for the Support Beam. Measure the distance between thelocation for the support beam 236 (FIG. 1) on the inlet end 160 of wye216 and the ground 124.

Step 1048—Cut a Support Beam. Cut a two by four or other suitable boardto form a support beam 150 with the length measured in the precedingstep. One of skill in the art will recognize that a jack stand or jackmay be used in lieu of a support beam.

Step 1052—Insert the support beam 150 to support the inlet end 160 ofthe injector assembly 200 as the injector assembly 200 will becomesignificantly heavier when filled with replacement material. One ofskill in the art will recognize that a small injector assembly 200 thatdoes not weigh an undue amount relative to the stiffness and length ofthe injector assembly may be operated without a support beam.

Filling the void.

FIG. 11 shows a sequence of steps 2000 for using a mounted injectorassembly 200 to deliver replacement material to a void 108.

Step 2004—Fill the Injector Assembly. Close the inlet valve 208 andoutlet valve 212. Remove the cap 204 (via camlock, threaded engagementor whatever is used to remove and replace the cap to hold it againstpressure). Use a scoop or other suitable tool to load replacementmaterial into the uncapped injector assembly 200. Depending on theheight of the opening to the injector assembly 200, it may be necessaryto use a step ladder or other lifting device. The lifting device may bea forklift platform or a scissor lift, or other device to allow accessto an injector assembly a distance above the ground.

Step 2008—Recap the Injector Assembly. Use a spray bottle to spray waterto remove replacement material from any location that would interferewith closing the cap 204. This is frequently necessary when using a capthat is removed and replaced through treaded engagement.

Step 2012—Pressurize the Injector Assembly. Attach an air hose to malecoupler 266 at the inlet end 160 of the injector assembly 200. The airhose should be connected to a source of compressed air such as aportable air compressor (not shown). One of skill in the art willappreciate that an oil-free compressor would be preferred in order toavoid injecting oil into the replacement material. The setting for theair compressor output will be a function of the air injector assemblyand may be limited by the type of replacement material used as somereplacement material may not tolerate being subjected to high pressuresas they may alter the properties of the replacement material anddivergence in ballistic properties relative to the replacement materialin the test cylinder. A suitable for air compressor setting for aninjector assembly made with schedule 80 PVC components is 25 psi (gagepressure). The pressure should be set before turning on the compressor.

As referenced above, the injector assembly may include a pressureregulator which will limit the pressure seen by the inlet valve 208 to aprescribed value such as 25 PSIG. A pressure gage may be placed inlinebefore the inlet valve 208 to allow the operator to ensure that thepressure regulation performed at the air compressor or at the pressureregulator is working to limit the pressure to within a prescribed rangeor limit. Open the inlet valve 208 to allow air pressure to pressurizethe injector assembly 200.

Step 2016—Open the Outlet Valve. Opening of the outlet valve 212 willcause the pressurized replacement material to move to through the outletvalve 212 through the second steel nipple 278 and out the injectorassembly outlet 290 on the distal face of the faceplate 140 into thelower pressure of the vented void 108. The void 108 does not becomepressurized as the vent hole 312 allows air to leave the void 108. Itmay be helpful to close the inlet valve 208 to allow the portable aircompressor to build up pressure and then open the inlet valve 208 tomove more replacement material. Once the replacement material has beensubstantially removed from the injector assembly 200, there will be aperceptible change in sound or vibration of the injector assembly 200 ascompressed air travels through the injector assembly 200.

Step 2020—Repeat Process to Completely Fill the Void. Unless replacementmaterial is seen leaving the upper opening in the vent hole 312, morereplacement material is needed. Repeat steps 2004, 2008, 2012, and 2016until replacement material leaves the upper opening in the vent hole312. Continue to use a spray bottle to spray water to remove replacementmaterial from any location that would interfere with closing the cap204.

Step 2024—Remove the Bulk of the Injector Assembly. After replacementmaterial seeps out the top of the vent hole 312, close the inlet valve208 and then the outlet valve 212. Remove the air compressor hose fromthe male coupler 266 at the inlet end 260 of the inlet valve 208. Rotatethe injector assembly 200 to unthread the outlet valve 212 from thefirst steel nipple 274 to leave the outlet valve 212 on the second steelnipple 278 that is attached to the steel plate 282 (proximal plate).

Step 2028—Clean the Removed Portion of the Injector Assembly. Clean theinjector assembly components thoroughly before the replacement materialhardens.

Step 2032—Wait for the Replacement Material in the Void to PartiallySet-Up. This may take in the range of 35-40 minutes depending on theweather conditions, the replacement material used, and other factors.The process of setting up can be observed by looking at replacementmaterial present on the inlet side of the outlet valve 212.

Step 2036—Remove the Outlet Valve. Once the replacement material in theoutlet valve 212 has set up sufficiently, unthread the outlet valve 212from the second steel nipple 278. Clean the outlet valve 212 thoroughly.

Step 2040—Remove the Proximal Plate. Remove the fasteners 304 that holdthe proximal plate such as steel plate 282 to the faceplate 140. Across-tip bit may be used depending on the fastener used. After theproximal plate is removed, replacement material will be visible througha corresponding 2 inch diameter hole in the faceplace 140. Once thereplacement material visible in the hole in the faceplate 140 issufficiently set up, then proceed to the next step.

Step 2044—Remove the Faceplate. Once the replacement material is set-up,remove the fasteners 308 holding the faceplate 140 to the proximal face112 of the ballistic panel 104.

Post-processing the replacement material.

FIG. 12 shows a sequence of steps 3000 to process the replacementmaterial after removal of the injector assembly 200.

Step 3004—Spray the Replacement Material with Water. Spray thereplacement material visible with the faceplate 140 removed to keep thearea moist so it can be worked.

Step 3008—Process the Plug Area. The process will leave a plug ofapproximately two inches of diameter that extends from the proximal face112 of the ballistic panel 104 as this material was extending throughthe opening in the faceplate 140 and at least partially filling thesecond steel nipple 278. Knock off the protruding plug and work thesurface of the replacement material over the entire surface of thefilled void to smooth the surface. Any marks from fasteners 304 thatextend beyond the faceplate 140 can be addressed in this step. Sprayedwater and troweling additional replacement material may be required.

Step 3012—Process the Vent Hole. Likewise, remove any protrudingmaterial from the vent hole 312 and work the area to provide a smoothsurface. Any holes from the fasteners 308 in the ballistic panel 104 canbe filled with replacement material at this time.

Step 3016—Let the Repaired Area Set. Let the repaired surfaces set forseveral minutes. Inspect to ensure that the surface of the repaired areahas set sufficiently to proceed to the next step.

Step 3020—Spray the Void and Vent Hole with Water. Soak the areas tosaturation.

Step 3024—Cover the Repaired Area. Place plastic film over the repairedarea and seal with duct tape to hold in the moisture on the repairs.Expect to see condensation on ballistic panel side of the plastic film.

Step 3028—Mark the Area with a No-Shoot Indicator. For example, onemight use bright red tape or other warning tape to mark the perimeter ofthe area to indicate that the repaired area should not be shot andshould not be behind a target that is used. A date may be written on thetape along with a unique identifier for the test cylinder in case thereare many different repairs and different test cylinders.

Step 3032—Test the Test Cylinder. After the replacement material in thetest cylinder has cured sufficiently for testing, test the test cylinderto ensure that replacement material meets the ballistic criteria.

Step 2036—Remove the Plastic and Warning Tape. After the test of thetest cylinder confirms that the replacement material meets the ballisticcriteria, the plastic film and all tape may be removed and this portionof the ballistic panel may be used without restriction.

Second Example of an Injector Assembly.

A second injector assembly 1200 is shown in FIG. 6 which is a side viewof an injector assembly 1200 connected to a ballistic panel 104 with avoid 108. More specifically, FIG. 6 shows a ballistic panel 104 with abase 120 on the ground 124 or some other support surface. A proximalface 112 of the ballistic panel 104 has a void 108 extending from theproximal face 112 a portion of the distance to the distal face 116. FIG.6 shows an injector assembly 1200 connected to a faceplate 140 which isremovably attached to the proximal face 112 of the ballistic panel 104by a set of fasteners such as screws 144 (See FIG. 5) such as concreteanchors. The faceplate 140 may be three quarter inch birch plywood.Optionally, a support beam 150 may be cut to the size needed to supportthe injector assembly 1200 in a substantially horizontal orientationwith respect to an opening in the faceplate 140 (discussed below). Thesupport beam 150 helps support the injector assembly 1200 as theinjector assembly 1200 will be filled with replacement material (notshown here) loaded into the injector assembly 1200 through an opening onthe top end of the injector assembly 1200 that is accessible afterremoving a cap 1204. Once the injector assembly 1200 is at leastpartially filled with replacement material and the cap 1204 replaced,air pressure may be used to inject the replacement material into thevoid through the use of inlet valve 208 and outlet valve 1212. (Valvesshown in FIG. 7)

FIG. 7 is a side view of the injector assembly 1200. The majority of theinterior volume for receipt of replacement material is found withininjector body 1220. The injector assembly 1200 shown in FIG. 7 uses aninjector body 1220 that is a manufactured nominal four inch aluminumpipe assembly that reduces to a nominal two inch pipe and has an inletprotrusion 1216. The three ends of the injector body 1220 are: thethreaded top 1228; inlet protrusion 1216; and outlet end 1274. Thus,injector body 1220 replaces the wye 216 and elbow 220 from FIG. 2.Injector body 1220 may be made from a material such as schedule 40aluminum pipe. Those of skill in the art will recognize that othermaterials can be used based on design choice for pressure used topressurize the injector assembly 1200, desire to hold down the weight ofthe injector assembly 1200, desire to have a durable assembly given theabrasive qualities of the replacement materials, and other designcriteria.

Both injector assembly 200 and injector assembly 1200 have a cap 204 or1204 located above a line running between the inlet valve 208 and theoutlet valve 212 or 1212. By having the opening in the top of theinjector assembly some distance above the valves, the upper portion ofthe injector assembly serves as a reservoir for replacement material. Asindicated in FIG. 7 the teachings of the present disclosure do notrequire that the upper portion of the injector assembly 1200 be orientedin a pure vertical orientation. Filling the injector assembly 1200 witha quantity of replacement material works well as long as the upperportion has a substantial vertical orientation. In many instances thismay be closer to pure vertical than 45 degrees but one could make aninjector assembly with an upper portion oriented at 30 degrees or someother angle less than 45 degrees as long as gravity helps deliverreplacement material to the portion of the injector assembly 1200between the inlet valve 208 and the outlet valve 1212.

A cap 1204 such as a four inch aluminum dust cap may be repeatedlyremoved and replaced via a camlock, threaded engagement, or other designchoice suitable for repetitive use in the field and the desire topressurize the injector assembly 1200. The combination of the cap 1204and the coupling adapter 1232 may be called the cap assembly 1202.

The outlet end of the injector body 1220 reduces to a two inch nominaldiameter. The inlet end 160 of the inlet protrusion 1216 has a one halfinch nominal diameter threaded opening which may be engaged by a brassnipple 248. An inlet valve 208 may be threadedly connected to the brassnipple 248. The inlet valve 208 may be a one half inch brass ball valvewith inlet valve handle 256. The inlet end 160 of the inlet valve 208may have a one half inch to one quarter inch brass bushing 262. A onequarter inch male coupler 266 extends from the bushing 262 to connect anair coupler 1294. A one half to one quarter inch bushing 262 connectsthe inlet end of the air coupler 1294 to a pressure regulator 1270.Another one half to one quarter inch bushing 262 connects the pressureregulator 1270 to a one quarter inch male coupler 266. An air hose froma compressed air source (not shown) may be connected to the one quarterinch male coupler 266 on the inlet end 160 of the injector assembly1200.

Those of skill in the art will recognize that other components withlarger or smaller interior diameters may be used to provide compressedair to the inlet protrusion 1216 without deviating from the teachings ofthe present disclosure.

Connected to the outlet end 1274 of the injector body 1220 is an outletvalve 1212 with actuator 1286. The outlet end 1274 of the injector body1220 may have a distal plate 1276 that may be a four inch square platethat is welded to surround the aluminum pipe to allow the outlet end1274 of the injector body 1220 to be bolted to the inlet end 160 of theoutlet valve 1212.

Note that a push-pull actuator with two handles on either side of theoutlet valve 1212 may be advantageous for use as the actuator 1286.Placement of the push-pull actuator such that the outlet valve 1212 isclosed when the actuator 1286 is in the up position allows downwardpressure against the pressurized replacement material which may be themore difficult change in valve position to be done with the least riskof dislodging the injector assembly from the support beam 150.Horizontal orientation for the push-pull actuator may be implemented ifadditional caution is used to avoid pushing the injector assembly 1200off the support beam 150. An injector assembly/support beam interactionthat would keep the injector assembly 1200 supported even after somehorizontal movement of the inlet end 160 of the injector assembly 1200may be acceptable. For a smaller injector assembly that is not supportedby a support beam, the outlet valve 1212 may be oriented so that theactuator 1286 is down when the valve is closed so that the force to movethe actuator is not added to the weight of the filled injector assembly1200 when the actuator 1286 is moved to open the pressurized injectorassembly 1200.

Those of skill in the art will recognize that there are a number ofdifferent valve designs that are used with fluids but will alsorecognize that some valve designs are more prone to fouling from thesand and grit in the replacement material, so certain valve choices willbe more reliable and durable than other choices. Many of the viablechoices will be types of gate valves such as knife valve, slide valve(sometimes called guillotine valve), or wedge valve.

Connected to the outlet end 164 of the outlet valve 1212 is the outletpipe 1278 which may be a two inch schedule 40 aluminum pipe welded to analuminum faceplate 1282. The outlet pipe 1278 has a proximal plate 1280that may be a four inch square plate that is welded to surround thealuminum pipe to allow the outlet pipe 1278 to be bolted to the outletend 164 of the outlet valve 1212.

While injector assemblies 1200 may be made of various sizes, an injectorassembly 1200 as shown in FIG. 7 may have a total length ofapproximately three feet from the from the distal face 1288 of aluminumfaceplate 1282 to the inlet end 160 of the male coupler 266 on the inletend 160 of the pressure regulator 1270. The length may be longer if anoptional pressure gage was included between the pressure regulator 1270and the inlet valve 208.

FIG. 8 is a front view of injector assembly 1200. Several componentsintroduced during the discussion of FIG. 7 are visible from a differentperspective in FIG. 8. Aluminum faceplate 1282 is shown with the distalface 1288 which would be facing the proximal face 112 of ballistic panel104 (see FIG. 6). The aluminum faceplate 1282 would be separated fromthe proximal face 112 of ballistic panel 104 by the faceplate 140 whichis sized to extend beyond the void 108 in all directions. The injectorassembly outlet 1290 is aligned with an opening in faceplate 140 toallow injection of a slurry of replacement material into the void 108.

Also visible in FIG. 8 are previously introduced components: cap 1204,coupling adapter 1232; injector body 1220, outlet valve 1212; andactuator 1286.

While injector assemblies may be made of various sizes, an injectorassembly 1200 as shown in FIG. 8 may have a total height ofapproximately twenty inches from the lower actuator 1286 to the top ofthe cap 1204 (excluding the camlock).

FIG. 9 is a top view of injector assembly 1200. This view showscomponents previously introduced from other views. Moving from the inletend 160 to the outlet end 164 the major visible components are: pressureregulator 1270, inlet valve 208 with inlet valve handle 256; cap 1204with camlocks, injector body 1220, outlet valve 1212 with actuator 1286,outlet pipe 1278 with aluminum faceplate 1282.

Alternatives and Variations.

Alternative Materials.

While examples provided above have named materials that may be used forspecific components such as aluminum, steel, plywood, brass, and PVC,those of skill in the art will recognize that other materials may besubstituted. The decision to change material may impact the weight ofthe injector assembly or the cost of the injector assembly but those ofskill in the art will understand those impacts and make decisions basedon particular needs.

Scaling.

The overall volume of replacement material that is loaded into ainjector assembly 200 or 1200 before being driven into the void 108 maybe varied by altering the diameters and lengths of components betweenthe outlet of the inlet valve 208 and the inlet out the outlet valve(212 or 1212). Changes to increase the volume will increase the weightof an empty injector assembly and the weight of a filled injectorassembly but will decrease the need for many cycles of loading withreplacement material to fill a large void 108.

Omission of Pressurization of Injector Assembly.

One of skill in the art will recognize that for certain uses of aninjector assembly, it may be sufficient to fill the injector assemblywith replacement material and open the outlet valve before opening theinlet valve so that there is not an intermediate act of pressurizing theinjector assembly before opening the outlet valve. Such a deviation fromthe process set forth in this disclosure should be viewed as analternative covered by the scope of this disclosure.

Use of Pressurized Gas other than Air.

While compressed air is a well-known item for use in construction sitesincluding remote sites as air compressors are made with a variety offuel options and tanks of compressed air are easy to carry to a remotesite, the process does not require that the compressed gas be air. Othergases can be used providing that they are compatible with thereplacement material (won't alter the replacement material) and safe foruse around those performing the procedure.

Alignment of Inlet and Outlet.

While the examples of injector assemblies 200 and 1200 show an inletapproximately horizontal with the outlet, this is not a requirement. Oneof skill in the art will appreciate that a pressurized gas inlet couldbe placed out of horizontal alignment with the outlet. For example, aninjector assembly inlet could be placed above the outlet. The inletcould even be placed above the removable cap.

If the inlet to the injector assembly was placed relatively highrelative to the outlet valve, one could potentially forego the inletvalve 208 and simply use a valve at the source of the compressed gas(such as a tank of compressed gas) or the controls for a compressor toturn on and off the provision of compressed gas through a pressureregulator.

Ballistic Material

The present invention includes a ballistic concrete as described in U.S.Pat. No. 9,121,675, issued Sep. 1, 2015 To Amidon et al., andincorporated herein by reference in its entirety.

The following definitions regarding the ballistic material are providedfor the benefit of the reader and are not limitations.

The term “fine aggregate” means natural sand (including quartz, chert,igneous rock and shell fragments), limestone (calcium carbonate),manufactured sand (crushed stone, recycled concrete, slag) ranging frommesh size #8 to #200 (2.4 mm to 0.07 mm) In preferred, non-limitingembodiments the fine aggregate is masonry sand (ASTM C 144) or generalconcrete sand (ASTM C 33) meeting the size criteria. In one non-limitingembodiment the fine aggregate is saturated surface dry (SSD) material,see ASTM C 128.

The term “fiber” means concrete additives to reinforce the concrete withmay be steel, alkali-resistant glass strands, or synthetic polymers. Inpreferred, non-limiting embodiments the fiber is a polyolefin, apolyester, a polyamide, (e.g., Kevlar®, nylon, polyester, polyethylene,polypropylene) or a mixture thereof, which may be a monofilament,fibrillated, or structured fibers (macrofibers). In one embodiment, thefibers meet ASTM C 1116 standards, such as ASTM C 1116 Type IIIrequirements for polypropylene or ASTM C 1116 Type I for steel.Non-limiting examples include Grace Fibers™ (W.R. Grace & Co.,Cambridge, Mass.); Nylon—N6600, Polyester—PE7, Polypropylene—CFP 1000,Polypropylene—PP7 (Concrete Fibers Inc., Dallas, Tex.); Nycon-MM,NYCON-PVA, Nycon-RECS100, Nycon-RF4000, Nycon-RSC15, Nycon-XL (NyconCorp., Fairless Hills, Pa.); ENDURO® 600, Fibercast® 500 for Precast,Fibercast® 510, Fibermesh® 150, Fibermesh® 300, Fibermesh® 650, Novocon®1050, Novocon® XR, Novomesh® 850, Novomesh® 950 (Propex Concrete SystemsCorp., Chattanooga, Tenn.); PSI Fibers™ (PSI Packaging, LaFayette, Ga.).Additional examples of suitable fibers include fibers described in U.S.Pat. No. 5,456,752 (Hogan); U.S. Pat. No. 6,423,134 (Trottier et al.);U.S. Pat. No. 6,582,511 (Velpari); or U.S. Pat. No. 6,758,897 (Rieder etal.), the contents of which are hereby incorporated by reference intheir entirety.

The term “air entrainment additive” means admixtures that are part ofthe ballistic concrete mix to incorporate air bubbles of controlledsizes in the ballistic concrete matrix. These admixtures stabilize theair bubbles entrained during the mechanical mixing of ballistic concreteby the mixer blades. Examples of air entrainment additives include, butare not limited to, DaraFill® Dry or wet DaraFill formulations (W.R.Grace & Co.), Rheocell® Rheofill™ (BASF Construction Chemicals,Cleveland, Ohio), Micro Air® (BASF Construction Chemicals), EUCON EASYFILL (Euclid Chemical Co., Cleveland, Ohio), Fritz-Pak Fill Flow(Fritz-Pak, Dallas, Tex.). Additional examples of air entrainmentadditives may be found in U.S. Pat. No. 4,488,910 (Nicholson et al.);U.S. Pat. No. 4,737,193 (Gutmann et al.); U.S. Pat. No. 4,249,948 (Okadaet al.); U.S. Pat. No. 4,046,582 (Kawamura et al.); or the PortlandCement Association publication entitled “Manual on Control of AirContent in Concrete” (PCA EB 116), the contents of which are herebyincorporated by reference in their entirety.

Air Entrainment Additives

Air entrainment additives generally include a surfactant. The surfactantcan be rosin-based or non-rosin-based. Other air-entraining materials,such as perlite, can also be used. The composition of some common airentraining additives follow:

Darafill—fatty alkanolamide 60% w/w, diethanolamine 4% w/w, perlite 60%w/w, quartz (crystalline silica) 0.50% w/w.

Rheocell Rheofill—Sulfonic acids, C14-16-alkane hydroxy andC14-16-alkene, sodium salts 75-100%; Benzenesulfonic acid, dimethyl-,sodium salt 5.0-15.0%.

Micro Air (hazardous ingredients only)—Alpha-olefin sulfonate 1-5% w/w;potassium hydroxide 1-5% w/w, rosin 0-1.0% w/w.

Eucon Easy Fill—Sodium (C14-16) Olefin Sulfonate 125-50% w/w

The term “depth of penetration” with respect to a bullet penetrationinto a barrier is measured by inserting a measuring implement into thehole formed by the bullet and measuring from the point of entry to thetrailing end of the bullet. Thus, the maximum penetration is actually abit deeper than the measured penetration as the bullet, while altered inshape from the impact has a non-zero length. The depth of penetration ofbullets into the absorbing material may be measured using alternativemethods known to those skilled in the art. Laser based tools such as alaser range finder may also be used.

Preparations of Bullet Absorbing Component

In a non-limiting formulation, the bullet absorbing components areprepared by mixing cement, fine aggregate, and water to form a grout.The grout may be obtained from a ready mix concrete supplier.

Next an air entrainment additive is mixed into the grout. Then calciumphosphate, aluminum hydroxide and fiber are added. After mixing for anumber of minutes the density is checked. As noted below, the additionof the calcium phosphate and aluminum hydroxide may be omitted ifpreventing lead leaching is not a concern.

If the mixture is above the target density range, additional mixing addsadditional entrained air bubbles to reduce the density. The process ofmeasuring density and providing additional mixing is repeated until themeasured density is within a target range of the optimal density.

When the density is deemed appropriate, the ballistic concrete is pumpedinto the void to fill it. Typically, the ballistic concrete is allowedto harden and cure for at least 4 weeks. Batching, mixing, transporting,testing, curing and placing the ballistic concrete would preferably meetthe standards described in the Army Corp. of Engineers guidelines“Technical Specification for Shock Absorbing Concrete (SACON®)”:

American Concrete Institute (ACI) Standards

ACI 117 (1990) Standard Specifications for Tolerances for ConcreteConstruction and Materials

ACI 301 (1999) Standard Specification for Structural Concrete

ACI 304R (2000) Guide for Measuring, Mixing, Transporting, and PlacingConcrete

ACI 305R (1999) Hot Weather Concreting

ACI 306R (1997) Cold Weather Concreting

ACI 544.1R (1996) State-of-the-Art Report in Fiber Reinforced Concrete

ACI 544.2R (1999) Measurement of Properties of Fiber Reinforced Concrete

American Society for Testing and Materials

ASTM C 33 (2001) Standard Specification for Concrete Aggregate

ASTM C 39 (2001) Standard Test Method for Compressive Strength ofCylindrical Concrete Specimens

ASTM C 94 (2000) Standard Specifications for Ready-Mixed Concrete

ASTM C 138 (2001) Standard Test Method for Density (Unit Weight), Yield,and Air Content (Gravimetric) of Concrete

ASTM C 144 (2002) Standard Specification for Aggregate for MasonryMortar

ASTM C 150 (2002) Standard Specification for Portland Cement

ASTM C 171 (1997) Standard Specification for Sheet Materials for CuringConcrete

ASTM C 172 (1999) Standard Practice for Sampling Freshly Mixed Concrete

ASTM C 567 (2000) Standard Test Method for Unit Weight of StructuralLightweight Concrete

ASTM C 1116 (2002) Standard Specification for Fiber-reinforced Concreteand Shotcrete

Us Army Corps of Engineers Handbook for Concrete and Cement (CRD)

CRD-C 400 (1963) Requirements for Water for Use in Mixing or CuringConcrete

National Ready-Mixed Concrete Association (NRMCA)

NRMCA QC 3 (January 1990; 9th Rev) Quality Control Manual: Section 3,Plant Certifications Checklist: Certification of Ready-Mixed ConcreteProduction Facilities

NRMCA CPMB 100 (January 1990; 9th Rev) Concrete Plant Standards

NRMCA TMMB 1 (1989; 13th Rev) Truck Mixer and Agitator Standards

The Portland cement used would preferably be ASTM C 150 Type I-II. Thefine aggregate may be masonry sand (ASTM C 144), or general concretesand (ASTM C 33).

The calcium phosphate may be granulated bone meal, bone ash, orprecipitated calcium phosphate. In one non-limiting embodiment, it istechnical grade or higher. The aluminum phosphate may be metakaoliniteor precipitated aluminum hydroxide. In one non-limiting embodiment, itis technical grade or higher. Color pigments may be optionally added tocreate the appearance rocks, trees, buildings, etc. Suppliers ofconcrete pigments include Scofield Co. (Douglasville, Ga.) or LambertCorp. (Orlando, Fla.). Thus, the present disclosure teaches the optionof pigmented bullet absorbing components.

The present disclosure teaches the creation of components made from wetballistic concrete prepared without an addition of preformed foam.

One of skill in the art of ballistic concrete manufacturing wouldrecognize that these materials are prepared on industrial scale andaccordingly quantities and proportions may vary in accordance withindustry norms. In addition, one skilled in ballistic concretemanufacturing would recognize that materials may be measured by volumeor by timed delivery from a storage container.

The following examples further illustrate the various teachings of thedisclosure and are not intended to limit the scope of the claimedinvention.

The bullet absorbing structural component made with ballistic concretecomprises:

(a) about 1 part by mass Portland cement;

(b) about 0.5 to 1.5 part by mass fine aggregate;

(c) about 0.005 to 0.15 part by mass fiber;

(d) about 0.005 to 0.05 part by mass calcium phosphate;

(e) about 0.005 to 0.05 part by mass aluminum hydroxide; and

(f) about 0.0005 to 0.05 part by mass air entrainment additive, suchthat the bullet absorbing component is capable of passing thepenetration test described above.

In one non-limiting embodiment, the bullet absorbing component comprises

(a) about 0.8 to 1.2 part by mass fine aggregate;

(b) about 0.008 to 0.012 part by mass fiber;

(c) about 0.008 to 0.012 part by mass calcium phosphate;

(d) about 0.008 to 0.012 part by mass aluminum hydroxide; and

(e) about 0.0008 to 0.002 part by mass air entrainment additive.

In another non-limiting embodiment, the bullet absorbing componentcomprises

(a) about 0.9 to 1.1 part by mass fine aggregate;

(b) about 0.009 to 0.011 part by mass fiber;

(c) about 0.009 to 0.011 part by mass calcium phosphate;

(d) about 0.009 to 0.011 part by mass aluminum hydroxide; and

(e) about 0.0009 to 0.0015 part by mass air entrainment additive.

The mixture comprising the Portland cement, the fine aggregate, thefiber; the calcium phosphate, the aluminum hydroxide, and the airentrainment additive may be mixed until the mixture has a density withina range of 88 to 94 pounds per cubic foot. The teachings of the presentdisclosure may be used to create a ballistic concrete without the use ofthe calcium phosphate and aluminum hydroxide if lead-leaching control isnot an objective.

In one non-limiting embodiment, the fiber may be a polyolefin fiber,which may or may not be fibrillated. In another embodiment the airentrainment additive is DaraFill® Dry.

The bullet absorbing component may have air bubbles resulting from theair entrainment additive that are less than about 0.04 inches (1 mm) indiameter. Alternatively, the bullet absorbing component may have airbubbles resulting from the air entrainment additive that are greaterthan 0.0004 inches (10 microns) in diameter. In another non-limitingembodiment, the bullet absorbing component has air bubbles resultingfrom the air entrainment additive that are less than about 0.04 inches(1 mm) in diameter and greater than 0.0004 inches (10 microns) indiameter.

The training with the live ammunition may be performed with at least oneof the following types of weapons:

.22 caliber weapon, .38 caliber weapon, .40 caliber weapon, .45 caliberweapon, 5.56 mm weapon, 6.8 mm weapon, 7.62 mm weapon, 9 mm weapon or agrenade or other fragmentation device.

Preparation of Components for Use Live Fire Ammunition

The ingredients for making the ballistic concrete components are asfollows:

Amount per unit ballistic concrete in Ingredient English System MetricSystem Portland Cement 972 pounds (441 kilograms); Fine Aggregate (SSD)972 pounds (441 kilograms); Water 466 pounds (211 kilograms); CalciumPhosphate 9.72 pounds (4.41 kilograms); Aluminum Hydroxide 9.72 pounds(4.41 kilograms); DaraFill® Dry 11.4 ounces (323 grams); Grace Fibers™14.8 pounds (6.71 kilograms).

FIG. 13 summarizes a process 4000 for making bullet absorbingcomponents. As noted below, some of the steps may be performed inslightly different orders but for sake of clarity, it is useful tointroduce one sequence of steps for discussion rather than muddy thewater with premature digressions on alternatives. The steps may besummarized as follows:

Step 4004—Obtain a grout of Portland cement, fine aggregate, and waterin a mixer in accordance with ACI standard 304R and/or ASTM standard C94. The act of obtaining includes creating the grout or obtaining thegrout from some third party.

Step 4008—Add a chemical air entrainment additive (DaraFill® Dry, W. R.Grace & Co.).

Step 4012—Following the addition of the additive, mix the grout for fiveminutes. Mixing may be achieved by rotating the drum on a cement mixertruck.

Step 4016—Add Calcium Phosphate, Aluminum Hydroxide, and fiber. Onesuitable fiber is Grace Fibers™. Mix for an additional ten minutes.

Step 4020—Check density such as by weighing using a ¼ cubic foot testingpot. Target weight is 22.7 pounds (approximately 91 pounds per cubicfoot) as the actual target is 91 pounds per cubic foot.+−0.3 pounds percubic foot.

Step 4024—Continue to mix if needed to reduce density to desired range.Additional mixing lowers the density. Continue to mix, checkingfrequently, until target density is achieved. The target wet densitymaterial when poured into components is 1458 kg/m·sup.3 (91-pounds percubic foot+3 pounds per cubic foot).

Step 4028—Pump ballistic concrete material into void. As withtraditional SACON® type ballistic concrete, vibration such as may beused with standard structural concrete is to be avoided to minimizedestruction of air bubbles.

Changes in Order and Additives.

Note that the step of adding the calcium phosphate and aluminumhydroxide could be done at the same time as adding the chemical airentrainment additive.

Note further, that as the calcium phosphate and aluminum hydroxide areadded to reduce lead-leaching from ballistic concrete blocks which haveabsorbed ammunition with lead components; these chemicals are notcentral to the ballistic properties of the ballistic concrete. Thus, inapplications where the need to reduce lead-leaching is not important(whether because of local rules, post use disposal plans, or a movementto ammunition with minimal or no lead), one can make ballistic concretein accordance with the teachings of the present disclosure withoutaddition of calcium phosphate or aluminum hydroxide.

The fiber may be added at the same time as the chemical air entrainmentadditive (and possibly the calcium phosphate and aluminum hydroxide) asthis process does not require achieving a pre-fiber density beforeadding the fiber. When the process is modified so that there is not aneed to add material after five minutes of mixing, simply mix forfifteen minutes before checking density. Additional mixing may berequired to reduce density.

Less Restrictions on Pouring.

Unlike traditional SACON® type ballistic material with fragile foambubbles, ballistic material made in accordance with the teachings of thepresent disclosure is not limited to a 2 foot maximum drop duringpouring or a 2 foot maximum depth of a pour. Thus, unlike traditionalSACON® type ballistic material, ballistic material made in accordancewith the teachings of the present disclosure may be poured into wallpanels oriented in their final vertical orientation. Optionally,ballistic material made in accordance with the teachings of the presentdisclosure may be poured into voids with pour heights well in excess of2 feet tall. Pours of greater than 3 feet in height are obtainable.Pours of greater than 6 feet in height are obtainable. Pours of greaterthan eight feet in height from bottom to top of a void are obtainable.Pour structures of full height walls of eight feet or more may be done.

The component is wrapped in plastic to assure adequate hydration duringcuring. One of skill in the art will recognize that the timing of thesesteps may be adjusted based on weather conditions, particularlytemperature but also factoring humidity. The components are allowed toharden and dry and are ready for use and/or testing after 28 days.

One of skill in the art will recognize that the fibers enhance thestrength and resilience of the components and ability of the repairedcomponents to withstand a bullet entry without spalling. Spalls areflakes of material that are broken off a larger solid body such as theresult of projectile impact, weathering, or other causes. It is desiredthat the repaired components retain their structural integrity with theexception of the trail formed by the bullet entry. Thus while the fibersare important, one of skill in the art can identify and substitute otherfibers that are suitable for the task, see e.g., paragraph defining termfiber in definitions section above. The choice of fibers will impact theoverall density of the wet material as the weight of the fibers impactthe density calculation.

Benefits of the Improved Bullet Absorbing Components

To date, the improved bullet absorbing components have consistentlyperformed well in ballistic testing. Anecdotal evidence suggestssignificantly higher failure rates for traditional SACON® ballisticconcrete than with the improved production process. These failure ratesmay be due to a lack of consistency of the product using traditionalSACON® ballistic concrete. The improved production process produces avery consistent material with an extremely low (much less than 1%)failure rate of the penetration test listed above.

Other benefits for the improved ballistic concrete are the predictableand uniform results in ballistic performance when the mix falls withinthe target density range. By uniform results, it is meant thatpenetration tests on different parts of a panel made with the improvedballistic panel will all pass the penetration test.

The process is sufficiently predictable that when a sample falls outsideof the target range for density after the prescribed mixing period, thisaberrant result is a strong indicator that the sand used in the mix isout of specifications, perhaps because of inclusion of clay or anothercontaminant.

Modification for Slower Projectiles

Those of skill in the art, recognize that the muzzle velocities fordifferent types of ammunition differs a considerable amount. Forexample, within pistols, the muzzle velocity of a 9 mm handgun issignificantly higher than the muzzle velocity of a 45 caliber pistol.The muzzle velocity for a given type of ammunition will actually dependon part on the length of the barrel of the gun.

In order to design a ballistic barrier for a lower velocity projectilethan used in the standard penetration test described above, theballistic barrier must be made easier to penetrate so that the back endof the projectile penetrates more than one inch into the ballisticbarrier. Increasing the amount of chemical air entrainment additive andor increasing the mix time to downwardly adjust the density target forthe ballistic material will enable the ballistic panel to be tuned foruse with a particular lower velocity projectile. Density of theballistic concrete may be dropped by simply mixing longer withoutchanging the amount of air entrainment additive. May need to augmentwith additional air entrainment additive for a severe change in density.

Modifications for Other Bullet Depth Ranges.

One of skill in the art could modify the teachings of the presentdisclosure to tune the ballistic concrete to capture a bullet from aprescribed round, firearm, and firing distance within a depth range thatis different from the 1 to 5 inch range referenced above. Thus, aballistic concrete component could be tuned to capture bullets in adepth range of 2 to 6 inches of depth as measured to the part of thebullet closest to the entry point, or 0.5 inches to 3 inches of depth asmeasure to the part of the bullet closest to the entry point.

Thus, in an example embodiment, a ballistic panel is formed with theballistic material herein described, the panel including a filled void,wherein the filled void is filled with a ballistic replacement material;and the filled void exhibits ballistic properties equivalent to theoriginal ballistic panel formed with the ballistic material.

The repaired ballistic panel has a uniform density of between about 1121kg/cubic meter (about 70 pounds per cubic foot) and about 1442 kg/cubicmeter (about 90 pounds per cubic foot). The ballistic replacementmaterial does not delaminate from adherence to the ballistic panel.

The ballistic panel with ballistic replacement material isshatter-resistant when struck with a bullet of between about 4 mm (.172caliber) with muzzle velocity about 120 m/s (390 ft/s) and about 12.7 mmweighing 600-800 grains (40-50 g) (50 caliber) with muzzle velocity of2800-3100 feet/sec (850-950 m/s) and kinetic energy of 12,000-15,000foot-pounds (17-21 kJ).

Retrofit of Existing Structures

In one embodiment, the present invention provides a method ofretrofitting a preexisting wall for bullet resistance comprising thesteps of: acquiring ballistic paver blocks; selecting a preexisting wallto be augmented; selecting a side of the preexisting wall to beaugmented; applying a row of the ballistic paver blocks in the firstlayer; applying subsequent rows of the ballistic paver blocks in thefirst layer; applying subsequent layers of the ballistic paver blocks.

In another embodiment, the present invention provides a bullet resistantwall comprising: ballistic paver blocks; wherein the ballistic paverblocks are arranged so as to create a wall with multiple layers; whereinthe multiple layers are formed through multiple rows of the ballisticpaver blocks.

In yet another embodiment, the present invention provides a bulletresistant wall comprising: ballistic paver blocks; wherein the bulletresistant wall does not contain any metal shielding or metal mesh.

The creation of stand-alone bullet resistant walls utilizing ballisticconcrete wall panels twenty-four to thirty inches thick for use in alive-fire training facility is well known in the art. These largestructures are appropriate as the walls need to withstand repeatedexposure to live fire while retaining an adequate ability to stopbullets from getting from one side of the ballistic concrete panel tothe other. However, such massive components require heavy equipment tomove and take up a large amount of space. Large concrete wall panelswould not be a convenient or practical solution for hardening a schoolor office building against penetration from a limited number of bullets.

In contrast, traditional building construction using steel stud framesor concrete masonry units (cinder blocks) will not stop a NATO M80 round(7.62 NATO) and the revised round known as the Enhanced PerformanceRound (EPR) can penetrate concrete masonry unit walls from forty toeighty meters depending on the rifle used. Filling a cinderblock wallwith mortar may add to the stability of the wall, but mortar does nothave stopping power for bullets or other projectiles. Additionally,solid filling the cinderblock walls with concrete would be expensive andrequire deconstruction of sections of wall. Thus, most buildings arevulnerable to bullets. In light of highly publicized attacks uponschools with a shooter armed with an assault rifle, there is an unmetneed to be able to harden preexisting walls in buildings.

Referring now to the drawings in general, the illustrations are for thepurpose of describing a preferred embodiment of the invention and arenot intended to limit the invention thereto.

FIG. 14 shows a sequence of steps 1000 to incorporate bullet resistanceinto a preexisting wall according to one embodiment of the presentinvention.

STEP 1004—Obtain a set of ballistic paver blocks for use in the project.In one embodiment of the present invention, the dimension of theballistic paver blocks is 12 inches by 12 inches by 3 inches. In analternative embodiment, the ballistic paver blocks have a surface faceof between 144 and 324 square inches. In an alternative embodiment, theballistic paver blocks have a surface face of between 16 and 64 squareinches. In an alternative embodiment, the ballistic paver blocks have asurface face of between 64 and 144 square inches. In one embodiment ofthe present invention, the ballistic paver blocks are square.Alternatively the ballistic paver blocks are rectangular. In a preferredembodiment of the present invention the ballistic paver blocks will beas large as is convenient for the application. Using larger paver blocksmeans fewer blocks to move and adhere to the wall. Additionally, largerballistic paver blocks create fewer seams and are desirable because abullet that happens to hit a seam may penetrate through the seam moreeasily than penetrating through a non-seam section of the ballisticpaver block.

In a preferred embodiment of the present invention, the ballistic paverblocks are made using ballistic concrete in accordance with the processset forth in U.S. Pat. No. 9,121,675, issued Sep. 1, 2015, which ishereby incorporated by reference in its entirety. Alternatively, theballistic paver blocks are made with SACON® ballistic concrete preparedfollowing the specifications set forth in the “Technical Specificationfor Shock Absorbing Concrete (SACON®)—Shock Absorbing Concrete forConstructing Live-Fire Training Facilities” and described in U.S. Pat.No. 6,264,735 issued Jul. 24, 2001, and U.S. Pat. No. 6,620,236 issuedSep. 16, 2003, which are hereby incorporated by reference in theirentirety. Alternatively, the ballistic paver blocks are made withballistic concrete prepared in some other manner where the ballisticconcrete is used to allow bullets to be captured rather than ricochetoff of the ballistic paver block when striking the paver blocksubstantially perpendicularly.

Step 1008—Select a preexisting wall to be augmented. In one embodimentof the present invention the preexisting wall is an interior wall.Alternatively the preexisting wall is an exterior wall. In oneembodiment of the present invention the preexisting wall is made fromconventional steel studs with drywall. Alternatively the preexistingwall can be made of concrete masonry units (CMUs—sometimes called cinderblocks). Alternatively the preexisting wall is made using any otherconventional building technique.

Step 1012—Select the side of the preexisting wall to be augmented. Inone embodiment of the present invention the preexisting wall is anexterior wall. When determining which side of the wall is to beaugmented, many factors are considered. By way of example and notlimitation, factors include the need to maintain interior squarefootage. In another embodiment of the present invention the ballisticpaver blocks are placed against the face of the preexisting wallanticipated to be closer to the shooter. Alternatively, the ballisticpaver blocks are placed against the face of the preexisting wallanticipated to be farther away from the shooter.

Step 1016—Level the floor or ground in the region that will receiveballistic paver blocks. This is an optional step as some buildings havewalls that are flat and level by the edge of the wall to be enhanced. Byway of example and not limitation, a user may snap a line to mark whatis level, then shim or use some other methods known to those skilled inthe art to get a level base for the ballistic paver blocks.

Step 1020—Apply a row of the first layer of ballistic paver blocks. FIG.15 illustrates a front view of a wall with a first layer of ballisticpaver blocks according to one embodiment of the present invention. Inone embodiment of the present invention the ballistic paver blocks are12 inches square and 3 inches thick. Alternatively the ballistic paverblocks can be in a different dimensional configuration depending onrequirements of the final product and the limitations associated withthe work space. In one embodiment of the present invention the row ispremeasured so that custom ballistic paver blocks fit flush against theabutting wall. In another embodiment of the present invention the wallis built with standard sized ballistic paver blocks and the lastballistic paver block before the end of the wall is cut with a saw. Theballistic paver blocks are readily field cut with a tile saw or othersaw used to cut analogous material.

For a wall that is to be protected that will abut another wall to beprotected in an inside corner, run the first row of the first layer ofthe first wall to be protected to the corner. Run the first row of thefirst layer of the second wall to be protected until making contact withthe first wall.

In a preferred embodiment of the present invention, the seams betweenadjacent ballistic paver blocks do not need to be filled withtraditional mortar as the flat edges of the ballistic paver blocks willfit together. This is advantageous as traditional mortar does not havebullet resistance characteristics, and thereby eliminating mortarreduces the surface of the wall that is not resistant to bullets.Additionally, any gaps in the seams for one layer of ballistic paverblocks will be covered by subsequent offset layers of ballistic paverblocks, thereby ensuring sufficient bullet resistance across the entireaugmented wall face. In another embodiment the gaps between ballisticpaver blocks is filled in with traditional mortar. This can beadvantageous to modify ballistic paver block spacing, thereby ensuringsubsequent ballistic paver block layers are offset from previousballistic paver block layers.

Step 1024—Adhere the ballistic paver block to the wall using a masticsuch as a landscaping mastic used for attaching stone or masonryelements in hardscaping. In one embodiment of the present invention theballistic paver blocks are adhered to the preexisting wall using aconstruction mastic. In another embodiment the ballistic paver blocksare adhered to the preexisting wall using an alternative adhesiveappropriate for the work environment. By way of example and notlimitation, a taller wall consisting of ballistic paver blocks requiresa stronger adhesive to ensure the stability of the augmented wall andsafety of those in its proximity. Those of skill in the art will be ableto select an appropriate construction adhesive for use with the presentdisclosure.

In one embodiment of the present invention the adhesive is placed onlyon the singular face of each individual ballistic paver block thatcontacts the preexisting wall or previous layers of ballistic paverblocks. In this configuration the adhesive is used to ensure theballistic paver blocks do not slip away from the wall. The combinedweight of the ballistic paver blocks is transferred down to the floorand therefore no adhesive on the bottom of the ballistic paver blocks isrequired. In another embodiment of the present invention, where theshape of the augmented wall warrants it, adhesive can be applied toevery side of the ballistic paver blocks.

Step 1028—Add the subsequent rows to the first row of the first layer ofballistic paver blocks. In a preferred embodiment each row of ballisticpaver blocks is offset from the row below (closer to the floor). By wayof example and not limitation, the first row starts with a 12 inch wideballistic paver block, the second row starts with a 4 inch wideballistic paver block, and the third row starts with an 8 inch ballisticpaver block, as illustrated in FIG. 16. The pattern then repeats untilthe top of the preexisting wall. Alternatively, the offset is 2 inches.Alternatively the offset is 3 inches. Alternatively the offset is 5inches. Alternatively the offset is the width of the ballistic paverblocks divided by the number of layers in the augmented wall. In apreferred embodiment of the present invention, the magnitude of theoffset from one row to the next is utilized in every layer of theaugmented wall, thereby preventing overlapping seams.

Step 2016—Apply a second layer of ballistic paver blocks. In a preferredembodiment of the present invention, the second layer of ballistic paverblocks are offset from the first layer of ballistic paver blocks so thatnone of the horizontal seams of the second layer of ballistic paverblocks align with the horizontal seams of the first layer of ballisticpaver blocks FIG. 17 illustrates a front view of a wall with a first andsecond layer of ballistic paver blocks according to one embodiment ofthe present invention. By way of example and not limitation, the firstrow of the second layer consists of ballistic paver blocks that are 4inches by 12 inches by 3 inches rather than the ballistic paver blocksmeasuring 12 by 12 by 3 used in the first layer. This offsets thehorizontal seams by 4 inches.

Additionally, the ballistic paver blocks are placed so that none of thevertical seams on the second layer of ballistic paver blocks matches upwith the vertical seams of the first layer of ballistic paver blocks. Inone embodiment of the present invention, a first ballistic paver blockof 4 by 4 by 3 inches is used and 4 by 12 by 3 inch ballistic paverblocks are used for the remainder of the first row across the floor. Thesecond layer is shown semi-transparent in FIG. 17. The next row isoffset a different amount than the second row of the first layer.Therefore the second row of the second layer is offset 8 inches ratherthan the 4 inch lateral offset of the second row of the first layer. Forexample, an 8×12 inch first block is used, with subsequent blocks being12×12. This process continues with ballistic paver blocks of the secondlayer being adhered to the first layer of ballistic paver blocks and thelast ballistic paver block in each row being field cut to fill theremaining space. The top row of ballistic paver blocks is field cut tofit the gap between the second to last row and the ceiling. One skilledin the art will realize that there are many variations of the presentinvention depending on the number of ballistic paver blocks available,size of wall, level of bullet protection needed, etc.

Step 2020—Apply the third layer of ballistic paver blocks. In apreferred embodiment of the present invention, the ballistic paverblocks of the third layer are arranged so that the vertical andhorizontal seams for the third row of ballistic paver blocks do notmatch the vertical or horizontal seams of the second or first layers ofballistic paver blocks. By way of example and not limitation, oneembodiment of the present invention consists of a 7 inch squareballistic paver block at the start edge on the floor and then completingthe first row with 7 inch by 12 inch ballistic paver blocks laid withthe 12 inch side parallel to the floor. FIG. 18 illustrates a front viewof a wall with three layers of ballistic paver blocks according to oneembodiment of the present invention. The third layer is shownsemi-transparent in FIG. 18. The subsequent rows of ballistic paverblocks on the third layer all start with a 7×12 inch ballistic paverblock. One skilled in the art will realize that there are manyvariations of the present invention depending on the number of ballisticpaver blocks available, size of wall, level of bullet protection needed,etc.

One of skill in the art will recognize that the offsets used to startthe second or third layer may be used for the first layer. The sequenceof layer offsets is not important so the repeating pattern of offsetsfrom vertical row to vertical row could be (0, 4, 8) (4, 8, 0); (8, 0,4) (8, 4, 0) (4, 0, 8) or (0, 8, 4).

Step 2024—Finish the outer surface of the top layer of pavers. In oneembodiment of the present invention the wall is finished with drywall.The drywall is attached to the top layer of ballistic paver blocks usingmasonry screws. Alternatively the drywall can be attached using othermethods. By way of example and not limitation, the drywall can beattached with adhesives. In another embodiment of the present inventionthe wall is finished with other surface treatments. By way of exampleand not limitation, the wall can be finished with paint. FIG. 18 is aside view of a finished wall with three layers of ballistic paver blocksand drywall.

Alternate embodiments of the present invention include augmenting theexterior face of walls. In one embodiment of the present invention,ballistic paver blocks on exterior side of an exterior wall are coveredwith conventional facades including, by way of example and notlimitation, brick, stucco, or masonry board. In another embodiment theexterior ballistic paver blocks are covered for ornamental appearance.Alternatively the ballistic paver blocks are covered to tacticallyconceal the location of augmented walls.

Test Results

A bullet resistant wall with three layers of 12 inch by 12 inch by 3inch ballistic paver blocks with offsetting vertical and horizontalseams, according to one embodiment of the present invention, was shotrepeatedly with a NATO M80 round (7.62 NATO) using an Armalite AR-10rifle with a 20 inch barrel. The shots were filed substantiallyperpendicular to the augmented wall. The distance from the gun to thewall was well under 82 feet and is thus unimportant as the velocity ofsuch a bullet is constant for the first 82 feet. The depths ofpenetration of the bullets measured from the outermost ballistic paverblock to the trailing end of the projectile were in the range of 2.5 to3 inches. This is a small fraction of the 9 inch total depth ofballistic paver blocks according to this embodiment of the presentinvention, so a second shot that hit the same bullet hole would not beable to traverse the ballistic paver blocks.

Alternative and Variations

In an alternate embodiment of the present invention, the ballistic paverblocks are applied to numerous walls to create a safe room. A safe roomis a place where staff and visitors or students retreat when there is anactive shooter situation. It is preferred that the safe room have a doorthat is itself resistant to bullets or other projectiles such as from agrenade.

While this disclosure has described a system that uses three layers of 3inch thick ballistic paver blocks, other combinations are possible.Those of skill in the art will recognize that not all three layers ofballistic paver blocks need be the same thickness. A designer may chooseto use two layers of ballistic paver blocks that are 4 inches thick andone layer of ballistic paver blocks that is 2 inches thick. The total ofthe layers does not have to add up to 9 inches. Depending on the type ofanticipated threat, the budget for the project, and the practicalconstraints of how much space can be consumed in a preexisting space, 9inches may not be the selected choice. An area that is only seeking tobe hardened against hand guns as it is unlikely that a rifle could becarried to that location may choose a lower level of bullet resistanceto add to interior walls.

A location seeking to harden exterior walls for a possible threat from a50 caliber sniper round might seek a larger total depth for the set oflayers. A location that may receive a number of bullets in a small areaof wall such as from a fully automatic weapon or a machine gun may seekto have a larger total depth for the set of layers.

The current disclosure expresses that a preferred embodiment has threeor more layers of ballistic paver blocks. Specifically, there is apreference for having three layers of 3 inch depth rather than twolayers of 4.5 inch depth. The advantage to numerous layers is that abullet that happens to hit a seam may penetrate through the seam moreeasily than had the bullet not hit the seam. Allowing a bullet to travelthrough a seam and then having just one layer beyond that seam to stopthe bullet might increase the risk that a bullet might penetrate theaugmented wall.

In a preferred embodiment of the present invention, the augmented wallcontains no additional metal in the form of metal plates or shielding.While it is well known in the prior art references to incorporate metalfor adding projectile resistance to structures, this is expensive andlabor intensive. Additionally, the added metal increases the weight ofthe final product. The present invention achieves the same, or better,level of protection from bullets and projectiles without the added cost,labor, or weight associated with utilizing metal components in the wall.

While the present disclosure expresses a preferred embodiment consistingof ballistic concrete pavers for all of the multiple layers, one ofskill in the art could choose to have one or more layers ofnon-ballistic concrete pavers with one or more layers of ballisticconcrete pavers. By way of example and not limitation, the first twolayers of ballistic paver blocks are followed by a non-ballistic paverblock layer. Alternatively, a first layer of non-ballistic pavers isfollowed by one or more subsequent layers of ballistic concrete.Alternatively the non-ballistic paver is in-between two layers ofballistic paver blocks. It is of note that having the outer layersformed with ballistic concrete will reduce ricochets and spalling.

Alignment of Seams

While the present disclosure taught the advantages of having threelayers with the ballistic paving blocks on each layer offset from oneanother so that the vertical seams and horizontal seams on any one layerdid not overlap a different layer, this is not absolutely required inorder to obtain many of the benefits of the present disclosure.

If the vertical and horizontal offsets are one third of the dimension ofan uncut square ballistic panel block, then embodiments of the presentinvention which incorporate four layers of ballistic paver blocks isgoing to repeat the seam pattern in two layers.

A user may choose to have offsets of one half of an uncut square blockso that the third layer repeats the seam pattern of the first layer.While this is not preferred embodiment, the chances of a bullet goingthrough the seam on the outermost layer, passing through the middlelayer where there is no seam and hitting exactly the seam on the bottomlayer is low.

Use of Tongue and Groove Pavers

The use of tongue and groove for ballistic barriers to address theconcern with seams is known. See U.S. Design Pat. No. D662, 225 issuedJun. 19, 2012, which is hereby incorporated by reference in itsentirety.

The use of tongue and groove could be used with ballistic paver blocksbut is not preferred. Adding tongue and groove complicates the moldingprocess with a ballistic paver block that is only a few inches thick.Specifically, the thin sections of tongue or grooves would be at risk ofbreaking. Additionally, tongue and groove would be more sensitive toimperfections from walls and floors that are imperfectly aligned. Tongueand groove would add complications when field cutting the pieces tocreate the seam offsets from layer to layer. However, especially ifthicker ballistic panel blocks were used, tongue and groove might haveappeal to some users.

In another embodiment of the present invention, the edges of theballistic paver blocks are tapered. By way of example and notlimitation, the vertical edges of the ballistic paver blocks are cut ata 45 degree angle to form beveled edges. FIG. 19 illustrates an exampleembodiment of blocks with two beveled edges according to the presentinvention.

This reduces the assembly and manufacturing difficulties associated withtongue and groove blocks while providing enhanced protection frombullets or projectiles that hit the seam.

Protection Against Explosive Devices

This disclosure has disclosed a method of creating a wall that ishardened to make it unlikely that certain types of bullets fired fromguns will traverse the wall protection. Nothing in this disclosureshould be interpreted as limiting the use of the ballistic paver blocksto thwart only bullets but not shrapnel from grenades and variousexplosive devices such as a backpack bomb, a pressure cooker bomb suchas used in the 2013 attack at the Boston Marathon, or other deviceswhich may be called an improvised explosive device. The benefits of thepresent disclosure include hardening walls to resist penetration of thewall from materials propelled from an explosive device.

Outlets and Other Utilities

In some instances an interior wall to be augmented with layers ofballistic paver blocks will have outlets for electricity, telephone orcomputer connections, or other utilities. Alternatively, an exteriorwall may have a water spigot. In some instances, the choice will be madeto retain these various utilities and cut the ballistic panel blocks toallow the old connections to be reached. In other instances, theutilities such as electrical or communication jacks will be extended andplaced on the new inside wall. In one embodiment, the wires are placedin a conduit to reduce the opening to be left in the layers of ballisticpaver blocks. Those of skill in the art will recognize that a bulletthat finds the openings through the layers of ballistic panel blocks maytraverse the wall and cause harm. The chances of a random shooterhitting a conduit path for an outlet from the other side of the wall islimited as there is not likely to be any indication on that side of thewall where the outlet or other utilities are located on the inside ofthe wall. A shooter is not likely to target a spigot on the exterior ofthe building.

Window Height Walls

In an augmented wall that incorporates windows, one embodiment of thepresent invention leaves the windows but adds layers of ballistic panelpavers to either surround the windows or to simply rise from the floorto the bottom edge of the windows. Alternatively, the ballistic paverblocks are added to the bottom 3 feet of the wall. Alternatively, theballistic paver blocks are added to the bottom 6 feet of the wall.Alternatively the ballistic paver blocks are added to the wall at aheight that coincides with the budget for the augmentation. Thesealternative embodiments are advantageous because persons in the roomwould be able to drop to the ground and be protected by the enhancedwall even while bullets striking the windows and possibly the uppernon-augmented section of walls may be penetrated, while also augmentingthe wall in the most cost-effective way.

Certain modifications and improvements will occur to those skilled inthe art upon a reading of the foregoing description. All modificationsand improvements have been deleted herein for the sake of concisenessand readability but are properly within the scope of the followingclaims.

What is claimed is:
 1. A ballistic panel formed with a ballisticmaterial, the panel comprising: a panel with a void, wherein the void iscreated by hits from projectiles; wherein the void in the panel isfilled with a ballistic replacement material such that the panelincludes a filled void including the ballistic replacement material;wherein the ballistic panel and the ballistic replacement material areformed from a concrete material with uniform density; wherein theballistic panel and the ballistic replacement material are formed fromwet ballistic concrete prepared without an addition of preformed foam;and wherein the filled void exhibits ballistic properties equivalent tothe ballistic panel formed with the ballistic material.
 2. The ballisticpanel of claim 1, wherein the uniform density of the ballisticreplacement material and the ballistic material is between about 1121kg/cubic meter (about 70 pounds per cubic foot) and about 1442 kg/cubicmeter (about 90 pounds per cubic foot).
 3. The ballistic panel of claim1, wherein the ballistic replacement material does not delaminate fromadherence to the ballistic panel.
 4. The ballistic panel of claim 1,wherein the ballistic replacement material and the ballistic materialare shatter-resistant when struck with a bullet between about 4 mm (.172caliber) and about 12.7 mm (50 caliber), moving at between about 120m/sec (390 ft/sec) and about 1,200 m/sec (3,900 ft/sec).
 5. Theballistic panel of claim 1, wherein the ballistic replacement materialand the ballistic material comprise: about 1 part by mass Portlandcement; about 0.5 to 1.5 part by mass of a fine aggregate; and about0.0005 to 0.05 part by mass of an air entrainment additive.
 6. Theballistic panel of claim 5, further comprising about 0.005 to 0.05 partby mass aluminum hydroxide and about 0.005 to 0.05 part by mass calciumphosphate.
 7. The ballistic panel of claim 5, further comprising about0.005 to 0.15 part by mass fiber.
 8. The ballistic panel of claim 7,wherein the fiber is a polyolefin fiber.
 9. The ballistic panel of claim8, wherein the polyolefin fiber is a fibrillated fiber.
 10. Theballistic panel of claim 5, wherein the air entrainment additive is amixture of a fatty acid ester and perlite.
 11. The ballistic panel ofclaim 5, wherein the ballistic replacement material and the ballisticmaterial include air bubbles resulting from the air entrainment additivethat are less than about 0.04 inches (1 mm) in diameter or greater than0.0004 inches (10 microns) in diameter.
 12. The ballistic panel of claim5, wherein the ballistic replacement material and the ballistic materialinclude air bubbles resulting from the air entrainment additive that arebetween about 0.0004 inches (10 microns) in diameter and about 0.04inches (1 mm) in diameter.
 13. The ballistic panel of claim 1, whereinthe ballistic replacement material and the ballistic material are madewithout an addition of a wet foam comprising water, a foaming agent, anda foam stabilizing agent.
 14. The ballistic panel of claim 1, whereinthe ballistic replacement material does not delaminate from adherence tothe ballistic panel.
 15. The ballistic panel of claim 1, wherein theballistic replacement material is shatter-resistant when struck with abullet between about 4 mm (.172 caliber) with muzzle velocity about 120m/s (390 ft/s) and about 12.7 mm weighing 600-800 grains (40-50 g) (50caliber) with muzzle velocity of 2800-3100 feet/sec (850-950 m/s) andkinetic energy of 12,000-15,000 foot-pounds (17-21 kJ).
 16. A ballisticpanel formed with a ballistic material, the panel comprising: a panelwith a void, wherein the void is created by hits from projectiles;wherein the void in the panel is filled with a ballistic replacementmaterial such that the panel includes a filled void including theballistic replacement material; wherein the ballistic panel and theballistic replacement material are formed from a concrete material withuniform density; wherein the ballistic panel and the ballisticreplacement material are formed from wet ballistic concrete preparedwithout an addition of preformed foam; wherein the filled void exhibitsballistic properties equivalent to the ballistic panel formed with theballistic material; wherein the ballistic replacement material and theballistic material comprise between about 1121 kg/cubic meter (about 70pounds per cubic foot) and about 1442 kg/cubic meter (about 90 poundsper cubic foot); and wherein the ballistic replacement material and theballistic material comprise: about 1 part by mass Portland cement; about0.5 to 1.5 part by mass fine aggregate; and about 0.0005 to 0.05 part bymass air entrainment additive; about 0.005 to 0.15 part by mass fiber;about 0.005 to 0.05 part by mass aluminum hydroxide and about 0.005 to0.05 part by mass calcium phosphate.
 17. The ballistic panel of claim16, wherein the fiber is a polyolefin fiber.
 18. The ballistic panel ofclaim 17, wherein the polyolefin fiber is a fibrillated fiber.
 19. Theballistic panel of claim 16, wherein the air entrainment additive is amixture of a fatty acid ester and perlite.
 20. The ballistic panel ofclaim 16, wherein the ballistic replacement material and the ballisticmaterial have air bubbles resulting from an air entrainment additivethat are between about 0.0004 inches (10 microns) in diameter and about0.04 inches (1 mm) in diameter.